ong periods of time. Natural thorium is almost 100 % 232^Th, with half life of 1.405*10^10y. If an average lateen mantle contains 350mg of thorium what is its activity (in Bq)

The half-life for the decay of carbon-14 is 5.73*10^3 years. Suppose the activity due to the radioactive decay of the carbon-14 in a tiny sample of an artifact made of wood from an archeological dig is measured to be 1.0*10^ 3Bq. The activity in a similar-sized sample of fresh wood is measured to be 6.9*10^3 Bq. Calculate the age of the artifact. Round your answer to 2 significant digits.

A piece of charcoal (totally carbon) from an ancient campsite has a mass of 262 grams.  It is measured to have an activity of 29 Bq from 14C decay.  Use this information to determine the age of the campfire.   Your answer is required to be in years. Information:    14C half-life is 5730 years. 1 gram of living carbon has 6.52x1010 atoms of 14C

iodine 131 has a half life of 8.04 days if you start with a radioactivr I 131 sample having an activity equal to 40 microci after how long is the activity going to be 4cmicroci

3. (a) Calculate the decay constant for cobalt-60 (T1/2 = 5.26 Years) in units of week-¹ (b) Calculate the activity of a 5000-Ci cobalt-60 source after 10 years.

An unknown element X has the following isotopes: ⁶⁴X (49.00% abundant), ⁶⁶X (28.00% abundant), ⁶⁸X (23.00% abundant). What is the average atomic mass in amu of X?

Modern household smoke detectors contain a tiny speck of the element Americium (Am, atomic number 95, atomic mass 241), which has a half-life of 432 years and an activity of (roughly) of 37,000 decays per second. a) What is the approximate mass of this speck? (Hint: the atomic mass of this isotope is approximately 241.06 u). b) This isotope is an alpha emitter. Is its radiation likely to be a hazard to the household members while the smoke detector is on the ceiling? Explain.

Carbon-14, with a half-life of 5730 years, has a decay constant of λ = 1.21 × 10-4 yr-1. A piece of wood from an archaeological site is found to have 1.9 % of its original carbon-14. How many years old (t) is the piece of wood? Express your answer in scientific notation. Example: 1.23e4.

a radioactive material has a half-life of eigth days. how long will take for the material to be reduce on one-sixteeth (1/16) of its original mass? a radioactive sample has a decay constant of 0.219/minute. what is its half-liofe?, if at the start of an exeperiement, there are 3.2x10 nuclei, how much wilkl remain after 1 hour?

Use the fact that there are 3.13x107 s/year. (a) The half-life of the radioactive nucleus 22688Ra is 1.58x103  years. What is the decay constant  (in s-1) of 22688Ra? (b) If a sample of 22688Ra nuclei has a decay rate of 3.9x105 decays /s at t = 0, then what is the decay rate after the sample is 4740 years old?